* {
  margin: 0;
  padding: 0;
}

body {
  background-color: #DCDFE6;
}

ul {
  height: 2400px;
  width: 1200px;
  margin: 20px auto;
  list-style: none;
}

ul li {
  width: 1200px;
  height: 600px;
  padding: 20px;
  border-radius: 15px;
}

ul li img {
  display: block;
  width: 1200px;
  height: 600px;
  border-radius: 15px;
}

button {
  width: 80px;
  height: 40px;
  border: 2px solid white;
  text-align: center;
  line-height: 40px;
  background-color: rgba(255, 0, 0, .6);
  position: fixed;
  right: 30px;
  bottom: 30px;
  cursor: pointer;
  display: none;
  color: white;
  transition: all 1s;
}

button:hover {
  background-color: rgba(255, 0, 0, .8);
}